Effect of high hot blast temperature on low-carbon ironmaking in large blast furnaces

With the global challenges of environmental sustainability and the pressing demand for sustainable development, low-carbon smelting in large blast furnaces (BFs) has become a critical pathway to achieving the “dual carbon” goals. Based on the fundamental principles of BF ironmaking, this study employs data analysis to examine the production practices of 25 large BFs in China with capacities exceeding 4000 m³ in 2023, focusing on the relationship between hot blast temperature and fuel consumption. The study systematically summarizes effective methods to increase hot blast temperature. Additionally, taking the production practices of a large BF in a Chinese enterprise as a case study, the paper elaborates on the influence of hot blast temperature on fuel consumption and proposes specific operational protocols and raw material parameters tailored to these findings. Analysis of production practice data from BFs demonstrates that through optimization of operational systems and refined management of raw material conditions, the average hot blast temperature in large Chinese BFs can be elevated to exceed 1250°C. Furthermore, when operating within the hot blast temperature range of 1125°C to 1245°C, incremental increase of 50°C in blast temperature enables a reduction of approximately 3–4 kg/t in carbonaceous fuel consumption.